基于交流电磁场的轨面疲劳裂纹量化检测方法研究

Alternative Current Field Measurement of Rail Rolling Contact Fatigue Crack

摘要:

钢轨滚动接触疲劳(Rolling Contact Fatigue, RCF)裂纹是影响轨道交通运行安全性与舒适性的主要原因之一,为了实现钢轨RCF裂纹形态参数的量化表示,采用交流电磁场检测(Alternative Current Field Measurement, ACFM)方法结合钢轨RCF裂纹现场取样观测结果建立了钢轨-裂纹-空气ACFM激励与响应计算模型；分析计算了ACFM对裂纹参数的响应情况,在此基础上结合线性插值与三次样条插值提出了钢轨RCF裂纹内部参数估算方法；搭建了基于函数波信号发生器、锁相放大器与数字信号采集仪的钢轨RCF实验检测台；制备了基于U型铁氧体磁芯、激励线圈、检测线圈的ACFM激励测量探头；基于钢轨RCF裂纹现场观测结果,进行了钢轨RCF裂纹的加工与实验测试；经过仿真计算与实验测试验证了所构建的钢轨RCF裂纹形态参数ACFM计算模型与内部参数估算方法；研究中的计算模型、实验平台与估算方法为进一步实现钢轨RCF裂纹的量化检测奠定基础。

Abstract:

Rail Rolling Contact Fatigue (RCF) crack is one of the main reasons affecting the safety and comfort of rail transit operation. In order to further quantitative estimate rail RCF crack morphology parameters, the calculation model of rail-crack-air electromagnetic excitation and response is established by using the method of alternative current field measurement (ACFM) and the field testing results of rail RCF crack. The response of ACFM to crack parameters is calculated and analyzed. A method for estimating crack internal parameters is proposed based on linear interpolation and cubic spline interpolation. The rail RCF test platform based on function wave signal generator, lock-in amplifier and digital signal acquisition instrument is built. An ACFM excitation-measuring probe is prepared based on U-shape core, excitation coil and detection coil. According to the field observation results of rail RCF crack, the machining and experimental testing of rail RCF cracks are conducted. Through simulation and experiment test, the built ACFM response model and the internal parameters estimation method are verified. The built calculation model, experimental platform and crack parameters estimation method in this study lay a foundation for further quantitative detection of rail RCF crack.